Exercise 12

Informatik_I/Exercise_12/Task_2a/README.org

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+#+tilte: Task 2a: Understanding Pointers - Num_Elements
+#+author: JirR02
+
+* Task Description
+
+  Complete the definition of function =num_elements= by editing the file =num_elements.cpp= according to its specified pre- and post conditions.
+
+  We provide a test program using the implemented function to find the number of elements in a specified interval of a vector.
+
+** Input
+
+   The test program accepts
+
+   - a vector length,
+   - the start index a, and
+   - the end index b.
+
+   For example
+
+   #+BEGIN_src shell
+   10 3 10
+   #+END_src
+
+   means a 10-element vector and the interval between index 3 and 9.
+
+** Output
+
+   The test program prints the number of elements in the interval [a,b).
+
+   For example the input given above, this value is 7.
+
+* Solution
+
+  #+BEGIN_src cpp
+  #include "num_elements.h"
+  #include <iostream>
+
+  // PRE: a <= b are valid pointers to elements of the same contiguous memory
+  // block. POST: Returns the number of elements in between those pointers
+  // (starting at a, not including b).
+  int num_elements(const int *a, const int *b) { return b - a; }
+  #+END_src
+
+  --------------
+
+  Made by JirR02 in Switzerland 🇨🇭